The present invention relates to an automatic exposure control device, a control device, an endoscope system, an automatic exposure control method, and the like.
An endoscope system has been widely used that applies illumination light to tissue in a body cavity, and allows the user to perform a diagnosis/procedure using an image signal generated from the light reflected by the tissue. The endoscope system (imaging device) may be configured so that an image sensor (e.g., CCD image sensor or CMOS image sensor) and an objective lens that optically forms an object image on the image sensor are provided on the end of the insertion section. A wide-angle objective lens is normally used as the objective lens of the endoscope in order to prevent a situation in which a lesion area is missed. For example, the viewing angle of a normal endoscope is about 140°.
JP-A-2010-169792 discloses an objective lens that makes it possible to simultaneously observe the object within the front field of view and the object within the side field of view in order to observe the object over a wider range.
An endoscope system is normally provided with a function of automatically adjusting the intensity of illumination light (i.e., dimming function) in order to acquire an object image having a brightness appropriate for observation using such an imaging optical system.